Compare the contents of both.

I personally will not feed RX food. Too expensive and there are just as good quality non rx foods out there. Reading labels paid off for us. Yes, it's a pain in the butt to stand in store and read labels or go on line and compare but it's worth it to find out rx food wasnt necessary.

It has been my experience with getting recommended by vet the "rx" food from their office, I was able to find Nutro line of food that when I told our vet about it he had no problem with Skinny eating this food. So that more less told me, I'm not paying the HIGH prices for speciality food at vet's office when there is just a comparable stuff out there for less money and does the same thing as Rx food.

Personally, Nutro food has cured tummy problems at my house. I swear by the stuff.